I am trying to find a table of the energy absorption coefficients (or mass energy absorption coefficients, I don't care because I can convert) in silicon dioxide for a variety of photon energies representative of x-rays and gamma rays. I expected this information to be easy to find because ionizing dose is a concern for electronic devices exposed to radiation, but the only tables that I found so far apply to various biological materials and not SiO2. Other types of attenuation coefficients can be found for SiO2 but these are not the same as the energy absorption coefficient.
I´m sorry, I don´t have a table and the normal source NIST provides no information. But I found two papers concerning attenaution coefficients in SiO2. Could be, it helps.
You can calculate this coefficient basing on data for nuclei.
It is: Kabs(SiO2)=(Kabs(Si)+2Kabs(O))*NA/MSiO2
Looked in the Rad Health Handbook. I have used these values for quartz windows and they appear accurate.
Thanks dear Joseph,
I didn´t know this handbook here in Germany. I immediately downlowded the 1970 version. Imposing data collection.
I appreciate all of the efforts but I think that all of the suggested references are about the attenuation coefficient rather than the energy absorption coefficient. The equation offered appears to be the Bragg rule which works great for coefficients (like the attenuation coefficient) associated with primary collisions by high-energy photons, but the energy absorption coefficient is something else. It pays attention to collisions by the incident photons and also to collisions by first-generation secondary electrons (and stopping power of electrons has a role). I'm not sure if the Bragg rule will work for this. I am going through an analysis to try to convince myself one way or the other about this. If somebody already knows whether the Bragg rule works for the energy absorption coefficient, that would eliminate a lot of work.
You can compute the energy absorption coefficient if you use the coefficients for the components (Si +O) by weighting the coefficients with the fraction per weight. For Si the value is 0.467435, for O 0,532565.The energy absorption coefficients can be calculated by
http://www.nist.gov/pml/data/xraycoef/index.cfm
The attached has the photoelectric and pair coefficients on page 65. A correction for bremsstrahlung may be necessary at higher energies.
Thank you all. I convinced myself that the Bragg rule (i.e., weighting the coefficients for the individual elements) should be okay for this application. Some of your suggestions were to do this and that increases my confidence that this should be okay.
Take a look here: XCOM (Photon Cross Sections Database) from NIST
https://physics.nist.gov/PhysRefData/Xcom/html/xcom1.html
Mass absorption Coefficient for SiO2
X-ray Density = 2.649 [gm/cm3]
Total Attenuation with Coherent Scattering : 3.643E+01 [cm2/gm]
at fixed angle = 90 deg & Photon Energy, 8keV,
cf. Wavelength and Photon Energy for Lab source Cu target : 1.542 Å ~ 8.04 keV
You can try the free software MUPLOT which can be found at the following link:
http://shape.ing.unibo.it/html/muplot.htm
To download, please go to the corresponding page. Let me suggest to compute the mass attenuation coefficients for the compound SiO2.
Kind regards
Jorge
Thank you, Professor Jorge Eduardo Fernández.
I downloaded the recommended MUPLOT program and ran it.
It is very similar to the literature mass absorption coefficients
and XCOM site from NIST vs. MUPLOT from University of Bologna
[Reference] B.D. Cullity et al., "Elements of X-Ray Diffraction",
Pearson Edu. Ltd. 2014, p. 363
For Cu Kα radiation, the mass absorption coefficient of BeO is 8.6, of SiO2 is 34.9, and of KCl is 124 cm2/g
Best regards
Suho Song
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